Cloud Basher, You don't mention your experience level but as someone who has flown the route you propose a few times over the years I would suggest you don't set your trip time and date in stone.Your px's will thank you for that. I have enjoyed some magic runs but have had some character building ones as well. eg fog problems Latrobe area, 180K past Sale @1000ft in a 135K aircraft, 85K down Ninety Mile Beach in the same aircraft,a 300ft drop in an airpocket at Cape Howe where the Roaring forties meet the South East Trade winds,low clouds and rain in the Woollongong area.Each of these occurred on different trips.Read your forecast carefully for the whole trip. On a good day you will have a wonderful trip. I hope I'm not teaching my Grandmother how to suck eggs.
Cheers RA